Bucket for placer dredges



-Aug. 4, 1925.

W. J. HALL BUCKET FOR PLACER DREDGES Filed Sept. 9, 1922 4 Sheets-Sheetl a H W 4 1925. fiw

W. J. HALL.

BUCKET FOR PLACER DREDGES Filed Sept. 9, 1922 4 Sheets-Sheet 2 Aug. 4,1925.

3,48 3% W. J. HALL BUCKET FOR PLACER DREDGES Filed Sept. 9, 1922 4Sheets-Sheet 3 Patented Aug. 4, 1925.

UNITED STATES 1,548,309 PATENT I OFFICE.

WILLIAM J. HALL, or 'oHIoAGo'HEIGfiTs, rLLINo-Is, GANESE STEEL COMPANY,or CHICAGO, ILLINOIS,

ASSIGNOR TO AMERICAN MAN- A CORPORATION OF MAINE.

BUCKET FOR PLACER DREDGES.

Application'filed September 9, 1922. Serial No. 587,052.

T 0 all whom. it may, concern:

Be it known that I, IVILLIAM J. HALL, a citizen of the United States,residing at Chicago Heights, in the county of Cook and State ofIllinois, have invented certain new construction of dredge bucket, themain body of which can be produced by casting, and can be successfullyand completely heat treated to properly condition the metal of which itis formed. The invention finds special application to dredge buckets ofthe kind which are operated in an endless chain,

and particularly to those of large capacity and heavy massiveconstruction.

In order that buckets of this type may withstand the severe shocks andwear to.

which they are subjected in use, special alloy steel, such as manganesesteel, is extensively used in their production. But the great variationin thickness of metal forming different portions of these buckets givesrise to many foundry problems, particularly when manganese steel isemployed in pro ducing them. One of the characteristics of manganesesteel is its high coefficient of expansion, amounting to as much as fths of an inch per foot. between the temperature at which the metal ispoured and the cold state, and this shrinkage has to be taken intoconsideration in order to avoid cracks and'mternal stresses that wouldbe detrimental to the casting.

Again, in the normal cast state, manganese steel is very brittle, beinga compound of austlnite (a solution of non manganese and the carbide ofiron and manganese) and free cementite (composed of the carbides of ironand manganese which remain undissolved). But since heating of the castmetal to proper temperature decomposesthe ce-.

mentite and renders the whole structure austinitic, whichlattercondition can be retained by plunging thecasting into cold water,and which condition produces a unique metal which is ductile, highlyresistant to wear and of great strength, the practice has grown up ofheat treating manganese steel castings. And here again the inequality inthickness of the various parts of a cast metal dredge bucket entersin tocomplicate the problem of production.

Cast manganese steel-can ordinarily be successfullyheat treated up' tosections of about four inches in thickness. Moreover, a

light section properly heat treated is much stronger and ofbetter shockresisting qual- 1ty than a heavy section improperly treated.

But it is not always practicable to reduce I sections of manganese steelcastings in cer.

ta in d1rections sufficiently to bring them within the temperingrange,owing to the necessity of maintaining high orders of strength in suchdirections, and a serious problem isoften presented in the design of'proper sections. This is particularly true with respect to the knucklesand eyes which constitute the hinging connections on dredge bucketswhere, in addition to opening up the metal to insure heat treatment,volume of metal must be maintained in. certain directions sufficient toinsure very high load car rying capacity. In practice, a single bucketof this type may embody upwards of a ton of metal in its structure, andmay enter into an endless chain of such buckets, developing -tensionalstrains upon their connecting knuckles and eyes amounting to many-tons,so thatereduotion in the section of such connections'in the direction ofloading is out of thequestion.

The present invention provides a construc t-ion of dredge bucket whichcan be successfully produced from manganese steel by,

casting and subsequent heat treatment, and the invention consists in theconstruction hereinafter described, whereby ample resistance to shocks,stresses, and erosion lmposedupon the bucket in use, is insured, and theportions of the structure which ordinarily present thicknesses in excessof those which can be successfully heat treated, are opened up orinteriorly exposed to heat conduction essential to uniform heating'and0001- In the accompanying drawings- Figures 1 and 2 are, respectively, aVertical central longitudinal section and a horizontal section of oneform of dredge bucket embodying the subject-matter of the invention; thesection of Figure 2 being in a plane indicated by the line'2 X of Figure1.

Figure 3 is a front elevation of one of the two symmetrically formedsides of the bucket.

Figures 4, 5, and 6 are detailed sections taken, respectively, in planesindicated by the lines 45-4", B -*5 and 6"6 of Figure 1.

Figures 7 and 8 are, respectively,a side elevation and a horizontalsection of another design of bucket in which the features of theinvention are embodied; the section of Figure 8 being in a planeindicated by the line 8"-8. of Figure 7.

Figure 9 is a front elevation of one of the two symmetrically formedsides of the hinging knuckle 4 (Figs. 1 and 2) or 4* (Figs. 7 and 8)transversely disposed across its rear end, and hinging eyes 5 (Figs. 1and 2) or 5 (Figures 7 and 8) spaced apart at its front end in positionto receive between them the hinging knuckle 4 or P to which they arepivotally connected by pintles passing through bores 6, 7, (Figs. 1 and,2) or 6, 7 (Figs. 7 and 8). It is also customary to provide dredgebuckets of this kind with bottom shoes 8 (Figs.

' 1 and 2) 0r8 (Figs. 7 and 8) upon which they are supported intraversing their bridge or track, and passing around the sprockets ortumblers at the end thereof.

But these knuckles, eyes, and shoes,'in order to develop resistance todestructive forces encountered 1n use, requlre to be made w th idimensions in excess of that whichcan be successfully heat treated inmanganese steel.

Thepresent invention admits oftheuse of dimensions for I thebefore-mentioned parts in the directions in which the destructive forcesare imposed upon them in use, but opensup' these parts in a manner toafford access of heat to and from the interior thereof in heat treatingand quenching or cooling. J

According to nels 9 running in planes parallel to the direction of drafttransmitted throughthe hinging, connection, and leaving, in positionsalternating with said channels, an-

Figures 1 and 2, the knuckle 4 is provided with a series of externalchannular strengthening sectors 10. According to Figures 7 and 8, thechannels 9 are of more uniform depth throughout the semicircumference ofthe approximately cylindrical hinging knuckle, thereby leaving annularstren hening sectors 10 of greater mass thant e sectors 10 of Figures 1and 2, which increased dimension will be desirable where the bucket isconstructed with great capacity. By means of the channels 9 or 9",considerable areas of the wall of the pintle bore are reduced to atransverse dimension which permits absorption and giving ofi of the heatentirely through the metal section, while the depth of the channels issuch as to expose lateral faces 10 or 10 upon the strengthening sectors10 and 10, thereby avoiding exclusion of heat from parts radially withinsaid sectors. In this way, a massive, substantially durable, andproperly heat-treated hinging knuckle is developed on the bucket.

In order to insure proper heat-treatment formed therein which servesimilarly to shoes or bottom may extendin any other desired directionwith similar results.

An important advantage in using the channels in the bottoms or shoes isthat they resist the peening action or flow of metal on the bottom ofthe bucket, due to pounding which the bucket receives in passing overrollers upon its bridge'or around the sprockets or tumblers at thev endsof the bridge.

In order to 5* in a manner to render them subject to thorou h heattreatment without detracting from tie strength-whichthey are required topossess in use, these eyes are recessed or opened up in one or anotherof several Ways, two of which are herein shown by way of illustration.

According to the construction shown in Fi vi ed with slots 12 extendinthrough the vertical and longitudinal imensions of said-eyes, except foran annular sector 13 left 'at the front of the eye in position to rendercontinuous the draft bearing of the form the hinging eyes 5 or x res '1,2, 3, and 6, the'eyes 5 are prohingingopintle throughout the transversedimension of the eye; lugs 14, projecting vided with a rearwardlyextending slot 17 which further opens u this portionof the metal; Theresult of t is'construction is a complete cylindrical wall definingthe-pintle bearing 6 to the extent of the thickness of the wall 15, anda bearing for said pintle limited to the front sector 13 in the outerwall 16 of the eye.

According to Figures 7 and 8, the eye is provided with an exteriorapproximately semi-annular groove 18 which leaves intact a.semi-cylindrical front bearing for. the pintle, and the entire lug ofthe eye member in rear of said semi-cylindrical bearing is slottedthrough from side to side, as shown at 19. Here, the elongated lugs 20are pr vided (see also F lgures 12 and 13) for the purpose ofdistributing heat to and from the adj acent parts, and positioning afiller block or other inserted piece, employed for completing thebearing.

To further open up the slide shoes, and

particularly in view of their relation to the v inclined'bottom 3, towhich they extend in H1 angular direction, these slide shoes may be.

provided with lateral recesses 21, 21, 22, 22 between them and thebottom 3,'which leave the slide shoes of reduced section. I I claim:

1. A cast metal dredge bucket formed at bottom with slide shoes andhaving channels intersecting said slide shoes, reducing the thickness ofthe metal thereof, and opening up said metal to the absorption andgiving off of heat in heat treatment of the casting.

, 2. cast metal dredge bucket constructed with an integral hinge knucklenear its bottom, and with slide shoes upon its bottom adjacent to saidknuckle; said knucklebeing provided with a transverse bore to receive apintle and having in the Wall of saidbore external channels leavingstrengthening ribs alternating with reduced wall sectors; and saidchannelsextending alon the slide shoes.

3. A cast metal dredge buc et having upon its bottom slide shoesintegral therewith, said slide shoes being provided with channels de; 1veloping areas of reduced thickness alternating with surface ribsvandexposingthe sides of said ribs and metal lying inwardly from thechannels to the absorption and giving ofl of'heat in the heat treatmentof the casting.

cast metal dredge bucket having an .inclinedbottom and slide shoesintegral with said bottom and extending at an angle thereto; sand slideshoes havingrecesses extending laterally thereinto between portions oftheir treads and the inclined bottom to 'open up and giving off of heatin heat treatment.

5. A cast metal dredge bucket having an integral hinging eye providedwith a bore to receive a pintle, and having a slot extending inwardlyfrom the pintle bore to open up the metal of the eye for the'absorptionand giving off of heat in heat treatment of the casting.

6. A cast metal dredge bucket having an integral hinging eye providedwith a bore to receive a pintle, andhaving a slot extending inwardlyfrom the pintle bore to open up the metal of theeye for the absorptionand giving oil of heat in heat treatment of the casting; said slot lyingin a vertical plane.

7.- Acast metal dredge bucket having an integral hinging eye providedwith a bore to receive a pintle, and having a slot extend. inginwardlyfrom the pintle bore to open up the metal of the eye for the absorptionand giving off of heat in heat treatment of the casting; said slot lyingin a vertical. plane and'extending through the eye to its forward end..v

g 8. A cast metal dredge bucket having an integral hinging eye providedwith a bore to receive a pintle, and having a slot extending inwardlyfrom the pintle bore to open up the metal of the eye for the absorptionand giving off of heat in heat treatment of the caste s;

ternal channel surrounding the front wall of its pintle bore.

9. A cast metal dredge bucket having an integral hinging eye providedwith a bore to receive a pintle, and having a slot extend,

ing inwardly from the pintle bore to open up the metal of the eye forthe absorption and giving off of heat in heat treatment of the casting;said slot lying in a horizontal plane; said eye being also provided withan external channel surrounding the front wall of its pintle bore; andsaid channel extending inwardly and merging with said slot.

10. A cast metal dredge bucket having an integral hinging eye providedwith a bore to receive a pintle, and having va slot extending inwardlyfrom the pmtle bore to open upthe metal of the eyefor the absorp tionand giving ofi of'he'at 1n heat treatment of the casting; said slotlying in a vertical plane; and the Walls of said slot being prosaid slotlying in a horizontal planef and said eye being also provided with anex.-

